Aggressive featured clips with improved tissue retention

ABSTRACT

A system for treating tissue includes a capsule including a channel extending therethrough; first and second clip arms each extending from a proximal end to a distal end, the proximal ends being received within the channel of a capsule to be moved between an open tissue receiving configuration; and a closed tissue clipping configuration. The first clip arm includes a first tissue retention feature at a distal portion thereof configured to pierce through a target tissue when in the tissue clipping configuration and subsequently release the target tissue when the clip arms are moved to an at least partially open configuration. The second clip arm includes a second tissue retention feature at a distal portion thereof configured to pierce and retain the target tissue thereon when in both the closed tissue clipping configuration and the open tissue receiving configuration.

PRIORITY CLAIM

The disclosure claims priority to U.S. Provisional Patent ApplicationSer. No. 62/735,728 filed Sep. 24, 2018; the disclosure of which isincorporated herewith by reference.

FIELD

The present disclosure relates to compression clips, and morespecifically, to compression clips delivered to a target site through anendoscope to cause hemostasis of blood vessels along thegastrointestinal tract.

BACKGROUND

Pathologies of the gastrointestinal (GI) system, the biliary tree, thevascular system, and other body lumens and hollow organs are oftentreated through endoscopic procedures, many of which require hemostasisto control bleeding. Hemostasis clips grasp tissue surrounding a woundand hold edges of the wound together temporarily to allow naturalhealing processes to permanently close the wound. Specialized endoscopicclipping devices are used to deliver the clips at desired locationswithin the body after which the clip delivery device is withdrawn,leaving the clip within the body. In addition to providing hemostasis,endoscopic clipping devices may also be used to provide, for example,endoscopic marking and closure of luminal perforations, e.g., fromendoscopic procedures involving access to internal tissue by passing adevice through a wall of a natural body lumen.

The opening width of the clips usually determine a maximum size of adefect that it can potentially close. To close a defect larger than amaximum clip opening width, several sophisticated closure techniqueshave been developed that often require the additional use of snares, “8rings”, or other devices. As an alternative to these advanced andtechnically challenging methods, a novel technique for defect closureuses a technique known colloquially “hold and drag” that makes itpossible to close sizable defects using only conventional clips. Thistechnique simplifies the closure of large defects and reduces the timerequired for the procedure. However, the biggest challenge in using thistechnique is the high risk of tissue slipping out if a clip is reopened.As a result, it is not uncommon that many attempts are required for thesuccessful closure of defects when applying this technique.

SUMMARY

The present disclosure relates to a system for treating tissuecomprising a capsule extending longitudinally from a proximal end to adistal end and including a channel extending therethrough and first andsecond clip arms each extending from a proximal end to a distal end, theproximal ends being received within a channel of a capsule to be movedbetween an open tissue receiving configuration, in which distal ends ofthe clip arms are separated from one another, and a closed tissueclipping configuration, in which distal ends of the clip arms are movedtoward one another, wherein the first clip arm includes a first tissueretention feature at a distal portion thereof configured to piercethrough a target tissue when in the tissue clipping configuration andsubsequently release the target tissue when the clip arms are moved toan at least partially open configuration and the second clip armincludes a second tissue retention feature at a distal portion thereofconfigured to pierce and retain the target tissue thereon when in boththe closed tissue clipping configuration and the open tissue receivingconfiguration.

In an embodiment, the first tissue retention feature includes a singlespike at a distal tip of the first arm and the second tissue retentionfeature includes two spikes at a distal tip of the second arm.

In an embodiment, the spikes extend from the distal tips of the firstand second arms at a 90 degrees angle relative to the longitudinal axisof the clip arms.

In an embodiment, when the clip arms are in the closed configuration,spikes on opposing clip arms are configured to be staggered.

In an embodiment, the first tissue retention feature includes at leastone spike at a distal tip of the first arm and the second retentionfeature is a hook extending from the distal tip of the second arm.

In an embodiment, the second tissue retention feature includes aplurality of barbs extending from an interior surface of the second cliparm.

In an embodiment, the barbs extend at a 90 degrees angle relative to alongitudinal axis of the second clip arm.

The present disclosure also relates to a reloadable clip devicecomprising an applicator including a catheter and a control memberextending therethrough, the control member extending from a proximal endto a distal end and being longitudinally movable relative to theapplicator, at least one clip assembly coupled to the applicator, eachclip assembly comprising: a capsule extending longitudinally from aproximal end to a distal end and including a channel extendingtherethrough, and first and second clip arms each extending from aproximal end to a distal end, the proximal ends being received within achannel of a capsule to be moved between an open tissue receivingconfiguration, in which distal ends of the clip arms are separated fromone another, and a closed tissue clipping configuration, in which distalends of the clip arms are moved toward one another, wherein the firstclip arm includes a first tissue retention feature at a distal portionthereof configured to pierce through a target tissue when in the tissueclipping configuration and subsequently release the target tissue whenthe clip arms are moved to an at least partially open configuration andthe second clip arm includes a second tissue retention feature at adistal portion thereof configured to pierce and retain the target tissuethereon when in both the closed tissue clipping configuration and theopen tissue receiving configuration.

In an embodiment, the first tissue retention feature includes a singlespike at a distal tip of the first arm and the second tissue retentionfeature includes two spikes at a distal tip of the second arm.

In an embodiment, the spikes extend from the distal tips of the firstand second arms at a 90 degrees angle relative to the longitudinal axisof the clip arms.

In an embodiment, when the clip arms are in the closed configuration,spikes on opposing clip arms are configured to be staggered.

In an embodiment, the first tissue retention feature includes at leastone spike at a distal tip of the first arm and the second retentionfeature is a hook extending from the distal tip of the second arm.

In an embodiment, the second tissue retention feature includes aplurality of barbs extending from an interior surface of the second cliparm.

In an embodiment, the plurality of barbs extend at a 90 degrees anglerelative to a longitudinal axis of the second clip arm.

In an embodiment, an interior surface of the first clip arm is flat.

The present disclosure also relates to a method of treating tissuecomprising inserting a first clip assembly to a target site within aliving body via a working channel of an endoscope, the first clipassembly including a capsule and first and second clip arms slidablyreceived within the capsule to be movable between an open configuration,in which distal ends of the clip arms are separated from one another,and a closed configuration, in which distal ends of the clip arms aredrawn toward on another, positioning the clip arms in contact with afirst target tissue, moving the first clip assembly from the openconfiguration to the closed configuration such that a first tissueretention feature on a distal portion of the first clip arm and a secondtissue retention feature on a distal portion of the second clip armpierces through the first target tissue, moving the first clip assemblyfrom the closed configuration to the open configuration, the firsttissue retention feature releasing the first target tissue while thesecond tissue retention feature retains the first target tissue thereon,positioning the clip arms in contact with a second target tissue andmoving the first clip assembly from the open configuration to the closedconfiguration to clip the first and second target tissues between thefirst and second clip arms.

In an embodiment, the first tissue retention feature is a spike.

In an embodiment, the second tissue retention feature is one of aplurality of barbs, a plurality of spikes and a hook.

In an embodiment, the method further comprises loading a first clipassembly on an applicator by coupling a control member of the applicatorto the proximal ends of clip arms.

In an embodiment, the method further comprises releasing the clipassembly from the applicator and loading a second clip assembly on anapplicator by coupling a control member of the applicator to theproximal ends of clip arms.

BRIEF DESCRIPTION

FIG. 1 shows a top plan view of a clip system according to an exemplaryembodiment of the present disclosure;

FIG. 2 shows a front view of a clip assembly of the clip system of FIG.1;

FIG. 3 shows a perspective view of distal ends of clip arms of the clipassembly of the clip system of FIG. 1;

FIG. 4 shows a perspective view of the clip assembly of the clip systemof FIG. 1;

FIG. 5 shows a top plan view of a clip system according to a secondexemplary embodiment of the present disclosure;

FIG. 6 shows a front view of a clip assembly of the clip system of FIG.5;

FIG. 7 shows a top plan view of a clip system according to a thirdexemplary embodiment of the present disclosure;

FIG. 8 shows a front view of a clip assembly of the clip system of FIG.7;

FIG. 9 shows a perspective view of distal ends of clip arms of the clipassembly of the clip system of FIG. 7;

FIG. 10 shows a top plan view of a clip system according to a fourthexemplary embodiment of the present disclosure;

FIG. 11 shows a front view of a clip assembly of the clip system of FIG.10;

FIG. 12 shows a side view of the distal end of a clip arm of the clipassembly of the clip system of FIG. 10.

FIG. 13 shows a first step of a method of use of the clip system of FIG.1;

FIG. 14 shows a second step of the method of use of the clip system ofFIG. 1;

FIG. 15 shows a third step of the method of use of the clip system ofFIG. 1; and

FIG. 16 shows a fourth step of the method of use of the clip system ofFIG. 1.

DETAILED DESCRIPTION

The present disclosure may be further understood with reference to thefollowing description and the appended drawings, wherein like elementsare referred to with the same reference numerals. The present disclosurerelates to a clipping system and, in particular, relates to a single useor reloadable endoscopic clipping system for treating tissueperforations, defects and/or bleeds. Exemplary embodiments of thepresent disclosure describe a hemostatic clip having aggressive grippingor retention features to improve attachment to target tissue when theclip is at least partially in an open configuration. In particular,exemplary embodiments describe a hemostatic clip with clip arms havingspikes, hooks, barbs and other geometries as gripping features to allowgrabbing and holding of tissue by a single clip arm. It should be notedthat the terms “proximal” and “distal,” as used herein, are intended torefer to toward (proximal) and away from (distal) a user of the device.

As shown in FIGS. 1, a system 100 according to an exemplary embodimentof the present disclosure comprises a clip assembly 102 insertable intoa living body through, for example, a working channel of an endoscope totarget tissue to be treated. The clip assembly 102 is sufficientlyflexible to permit it to traverse a tortuous path through the body—e.g.,passing through the working channel of a flexible endoscope insertedthrough a natural body lumen accessed via a natural bodily orifice. Inan exemplary embodiment, the clip assembly 102 is loadable onto a distalportion of an applicator 104 prior to insertion of the clip assembly 102into a living body for the clipping of target tissue. The applicator 104and the clip assembly 102 are configured so that, after deployment ofthe clip assembly 102 in the living body, a new clip assembly 102 may beloaded onto the applicator 104 so that the same applicator 104 may beused to deliver a new clip assembly 102 to a second portion of targettissue in the living body. The applicator 104 may include a catheter(not shown) and a control member 108 extending therethrough. The clipassembly 102 includes first and second clip arms 110, 112 slidablyreceived within a longitudinal channel 114 of a capsule 116. The firstand second clip arms 110, 112 can be moved between an open tissuereceiving configuration, in which the distal ends 120, 122 of the cliparms 110, 112, respectively, are separated from one another to receivetarget tissue therebetween, and a closed tissue gripping configuration,in which the distal ends 120, 122 of the clip arms 110, 112 are movedtoward one another to grip the target tissue therebetween. The clip arms110, 112 are movable between the open and the closed configurations viathe control member 108 extending into the capsule 116. A proximal end(not shown) of the control member 108 is connected to an actuator on ahandle positioned outside of the human body. In this embodiment, adistal end of the control member 108 is coupled to proximal ends of theclip arms 110, 112.

As further shown in FIG. 1, the clip arms 110, 112 according to anexemplary embodiment of the present disclosure which extend fromproximal ends (not shown) to the distal ends 120, 122. As those skilledin the art will understand, arms 110, 112 of this embodiment are biasedtoward an open tissue receiving position in which the distal ends 120,122 are separated from one another to receive tissue. That is, the arms110, 112 are formed so that they spring open to the tissue receivingposition when they are moved distally out of the constraint of thecapsule 116. However, as would be understood by those skilled in theart, the clip assembly 102 may include a separate member urging the cliparms 110, 112 away from one another in addition, or as an alternative,to this bias. In an exemplary embodiment, the clip arms 110, 112 mayinclude locking tabs (not shown) at their proximal ends for engagingdistal components within the capsule 116 when the clip assembly 102 hasbeen deployed. Locking tabs (not shown) may also form a mechanical lockwith windows formed on lateral sides of the capsule 116 after the cliphas been deployed. However, those skilled in the art will understandthat any of the various known mechanisms for releasably coupling a clipassembly 102 (e.g., a capsule including clip arms) to an insertiondevice may be employed without deviating from the scope of theinvention. As indicated above, the clip arms 110, 112 are biased towardthe open configuration so that, when the clip arms 110, 112 are moveddistally past a distal end 126 of the capsule 116, distal ends 120, 122of the clip arms 110, 112 separate from one another to the openconfiguration. When the clip arms 110, 112 are drawn proximally into thecapsule 116, contact with the capsule 116 draws the clip arms 110, 112toward one another to the closed configuration. Upon deployment, theclip arms 110, 112 are locked within the capsule 116 which holds them inthe closed position as would be understood by those skilled in the art.As described above, the clip arms 104, 106 are moved between the openand closed configurations via the control member 108, which is movedproximally and distally relative to the capsule 116 via an actuator at ahandle that remains outside the body.

In an exemplary embodiment, one or both of the clip arms 110, 112 mayinclude spikes 128 extending from an interior side of a distal tip 130of the clip arms 110, 112. As shown in FIGS. 2-3, the first clip arm 110has a single spike 128 while the second clip arm 112 has two spikes 128.The spikes 128 extend substantially perpendicularly from the interiorface of the clip arms 110, 112 radially inward toward the other of theclip arms 110, 112. In an exemplary embodiment, the spikes 128 aredesigned to pierce or at least engage the tissue such that the tensionin the tissue (from pulling it across the defect) creates moreengagement between the spikes 128 and the tissue. For example, afishhook shape demonstrates this engagement once it pierces the tissue:application of additional force in the same direction pushes the tissuefurther up the hook while the direction of force must be reversed toremove the hook. As can be seen in FIG. 3, the spikes 128 on opposinganus 110, 112 are offset from one another longitudinally so that they donot prevent complete closure of the clip arms 110, 112 around the tissuedefect. For example, as shown in FIG. 3, the spike 128 of the first cliparm 110 is positioned one of distally or proximally of the two spikes128 on the second clip arm 112 when the clip assembly 102 is in theclosed configuration. Furthermore, as shown in FIG. 4, the spikes of thefirst and second clip arms 110, 112 are offset from one anotherlaterally so that the spike 128 of the first clip arm 110 is receivedbetween the spikes 128 of the second clip arm 112 without anyinterference. In an alternate embodiment, the spikes 128 are configuredto extend in different planes to be received by an opposing arm withoutinterference from the spike 128 of the other arm. For example, the spike128 of the first clip arm 110 is positioned so that it fits between thetwo spikes 128 of the second clip arm 112 when the clip assembly 102 isin the closed configuration. In another embodiment, both of the spikes128 are configured to extend in substantially the same plane so thatwhen arms 110, 112 are in a closed configuration ends of the spikes 128from opposing arms 110, 112 touch one another. As would be understood bythose skilled in the art, the spikes 128 are sufficiently sharp topierce through tissue and hook therein. In an embodiment, the spikes 128of the second clip arm 112 are angled to a greater degree with respectto the rest of the clip arm 112 so that the spikes 128 remain hookedwithin the target tissue when the clip assembly 102 is moved to the openconfiguration to capture another portion of tissue. Specifically, thespikes 128 may likewise extend from the interior face of clip arm 112 atvarious angles between 20 and 90 degrees relative to the longitudinalaxis L of the clip arm 112 to allow the spikes 128 to continue to grabthe tissue when the clip arms 110, 112 are in the open configuration.

In use, the operator will orient the clip arms 110, 112 so that thesecond clip arm 112 will be on the outside of the tissue defect and thefirst clip arm 110 is on the inside of the tissue defect. Next, theoperator will close the clip assembly 102 on the edge of the tissuedefect and the spikes 128 will pierce through the mucosal layer to keepthe tissue inside the clip anus 110, 112. When the clip assembly 102 isdragged to the opposite edge of the tissue defect and gently reopened,the tissue flap will still be hooked onto the second clip arm 112 butreleased from the first arm 110. That is, the direction of force of thefirst clip arm 110 is reversed so that the tissue is unclipped from thefirst clip arm 110 while remaining on the second clip arm 112. The firstclip arm 110 can then be used to draw the opposite edge of the defectinside the clip assembly 102. The spikes 128 on both jaws 110, 112 willensure that the edges of the defect are securely captured and will notslip out when the clip is closed and deployed. When the two opposingedges of the tissue defect are connected by the clip assembly 102, theclip assembly 102 will be released from the applicator 104 and furtherclips can be placed along the tissue defect to finalize the closure, aswill be described in further detail below.

In another exemplary embodiment, shown in FIGS. 5-6, a system 200 issubstantially the same as system 100 except as described herein. Thesystem 200 includes a clip assembly 202 with first and second clip arms210, 212. In this embodiment, the clip arms 210, 212 use a combinationof hooks and spikes to retain a first tissue edge on one arm whiledragging a second tissue edge toward the first edge with the second arm.Specifically, as shown in FIG. 5, the first arm 210 includes two spikes228, similar to the spikes 128 of the clip assembly 102, extendingsubstantially perpendicularly from the interior face of the clip arm 210radially inward toward the second clip arm 212. The second arm 212 has ahooked distal end 222 with a sharp distal-most tip 230 configured topierce and retain tissue thereon. In an exemplary embodiment, the distaltip 230 is angled at approximately 90 to 180 degrees relative to therest of the clip arm 212. For example, in an embodiment, the distal end222 of the second clip arm 212 may be bent back toward the clip assembly202 such the distal tip 230 is approximately parallel to the rest of theclip arm 212. This embodiment provides a high degree of tissue retentiononce the distal tip 230 has pierced the tissue defect. In anotherexample, the distal end 222 may have a greater than 90 degree bend suchthat distal tip is substantially perpendicular to the proximal portionof the clip arm 212. This embodiment allows the tissue defect to be moreeasily pierced by the distal tip 230.

In use, the hooked distal end 222 of the second clip arm 212, asdiscussed above, is designed to adhere to the tissue and keep a firstedge of the tissue defect inside the clip arms 210, 212 while the spike228 of the first clip arm 210 is designed to release the first edge ofthe tissue defect and draw the opposite second edge of the tissue defectin when the clip assembly 202 is reopened. This combination ofaggressive features has demonstrated to be especially effective for the“hold and drag” technique.

In another exemplary embodiment, shown in FIGS. 7-9, a system 300 issubstantially the same as systems 100, 200 except as described herein.The system 300 includes a clip assembly 302 with first and second clipanus 310, 312. The first clip arm 310, in this embodiment, includes oneor more barbs 332 attached to an interior face 334 of a distal portionof the first clip arm 310. Clip arms with barbs are especially effectiveif the operator can force the barbed arm flat against the target tissue.This positioning of the arm flat against the tissue allows each of thebarbs 332 to pierce the submucosal tissue layer and force the tissue tostay attached to the clip arm even under high tension. As shown in FIGS.8-9, the first clip arm 310 of this embodiment includes four barbs 332which extend substantially perpendicularly from the interior face 334 ofthe first clip arm 310 radially inward toward the second clip arm 312.It will be understood that while the present embodiment includes fourbarbs 332, any number of barbs may be used. The barbs 334 may likewiseextend from the interior face 334 at various angles between 20 and 90degrees and, more particularly, 45 degrees relative to the longitudinalaxis L of the clip arm 310 to allow the barbs 332 to grab tissue whenthe clip arms 310, 312 are in the open configuration. That is, the barbs332 may extend outward from the interior face 334 of the first clip arm310 in a plane substantially perpendicular to a plane containing theinterior face 334 of the first clip arm 310 or may extend at an angleand thus in a plane that is not perpendicular to the plane containingthe interior face 334 of the clip arm 310. In an embodiment, shown inFIGS. 8-9 the barbs 332 are positioned on the interior face 334 as pairsthat are substantially parallel with one another. However, it isunderstood that the barbs 332 may take any configuration such as, forexample, longitudinally staggered pairs, a single longitudinal linealong a central longitudinal axis of the clip arm 310, etc. As can beseen in the figures, the second arm 312 has a flat profile along itslength.

In addition to spikes, hooks and barbs, other geometries can be used toimprove attachment of clip arms to the target tissue defect. Forexample, in another exemplary embodiment, a clip assembly 402 of a clipsystem 400, shown in FIGS. 10-12, includes sharp teeth 440 at the distaltip 430 of at least one of first and second clip arms 410, 412. Forexample, as can be seen in FIGS. 11-12, the first clip arm 410 includesthree teeth 440 positioned at an inner surface of the distal tip 430 ofthe first clip arm 410. It is noted that while this embodiment includesthree teeth, any number of teeth may be used, as would be understood bythose skilled in the art. The teeth 440 have sharpened tips to allow fortissue piercing and retention. Additionally, the distal tip 430 of thefirst clip arm 410 may be angled at approximately 90 degrees relative tothe remainder of the clip arm 410 to allow for tissue retention when theclip arms 410, 412 are reopened.

A method of use of system 100 according to an exemplary embodiment isdepicted in FIGS. 13-16. Initially, the clip assembly 102 is insertedthrough a working channel of an endoscope (or any other insertiondevice) and inserted into the body (e.g., through a natural body lumen)to a site adjacent to a target defect 10 of tissue to be clipped closed.The clip assembly 102 is inserted to the target tissue in the closedconfiguration to facilitate its passage through the working channel.Upon reaching the site of the target tissue defect, the clip assembly102 is advanced out of the distal end of the working channel of theendoscope and the clip arms 110, 112 are extended out of the capsule 116to move the clip arms 110, 112 to the open tissue receivingconfiguration. Once a first edge 12 of the tissue defect target tissuehas been received between the clip arms 110, 112, the clip arms 110, 112are moved toward the closed configuration so that the spikes 128 piercethe first edge 12 of the tissue defect so that the first edge 12 isgripped between distal ends of the clip arms 110, 112. The clip arms110, 112 are moved toward the tissue gripping configuration by drawingthe control member proximally with respect to the capsule 116. Once theclip assembly 102 is in the closed tissue gripping configuration, thefirst edge 12 is dragged towards the second edge 14 of the defect viathe clip assembly 102, via the applicator 104. When the first and secondedges 12, 14 of the tissue defect are adjacent to one another, the cliparms 110, 112 are gently reopened. As the clip arms 110, 112 arereopened, the first arm 110 releases the first edge 12 of the tissuedefect but the two spikes 128 of the second clip arm 112 keep the firstedge 12 attached to the second clip arm 112. The clip arms 110, 112 aresubsequently re-closed over both edges 12, 14 of the tissue defect andthe first clip assembly 102 is deployed from the applicator 104 via theactuator. Additional clip assemblies 102 may be placed along the tissueedges to close the defect.

It will be appreciated by those skilled in the art that changes may bemade to the embodiments described above without departing from theinventive concept thereof. It should further be appreciated thatstructural features and methods associated with one of the embodimentscan be incorporated into other embodiments. It is understood, therefore,that this invention is not limited to the particular embodimentdisclosed, but rather modifications are also covered within the scope ofthe present invention as defined by the appended claims.

1-15. (canceled)
 16. A system for treating tissue, comprising: a capsuleextending longitudinally from a proximal end to a distal end andincluding a channel extending therethrough; and first and second cliparms each extending from a proximal end to a distal end, the proximalends being received within a channel of a capsule to be moved between anopen tissue receiving configuration, in which distal ends of the cliparms are separated from one another, and a closed tissue clippingconfiguration, in which distal ends of the clip arms are moved towardone another, wherein the first clip arm includes a first tissueretention feature at a distal portion thereof configured to piercethrough a target tissue when in the tissue clipping configuration andsubsequently release the target tissue when the clip arms are moved toan at least partially open configuration and the second clip armincludes a second tissue retention feature at a distal portion thereofconfigured to pierce and retain the target tissue thereon when in boththe closed tissue clipping configuration and the open tissue receivingconfiguration.
 17. The system of claim 16, wherein the first tissueretention feature includes at least one spike at a distal tip of thefirst arm and the second tissue retention feature includes two spikes ata distal tip of the second arm.
 18. The system of claim 17, wherein thespikes extend from the distal tips of the first and second arms at a 90degrees angle relative to the longitudinal axis of the clip arms. 19.The system of claim 16, wherein when the clip arms are in the closedconfiguration, spikes on opposing clip arms are configured to bestaggered.
 20. The system of claim 16, wherein the first tissueretention feature includes at least one spike at a distal tip of thefirst arm and the second retention feature includes at least one hookextending from the distal tip of the second arm.
 21. The system of claim16, wherein the second tissue retention feature includes a plurality ofbarbs extending from one of an interior surface and a side surface ofthe second clip arm.
 22. The system of claim 21, wherein at least one ofthe barbs extends at a 90 degrees angle relative to a longitudinal axisof the second clip arm.
 23. A reloadable clip device, comprising: anapplicator including a catheter and a control member extendingtherethrough, the control member extending from a proximal end to adistal end and being longitudinally movable relative to the applicator;at least one clip assembly coupled to the applicator, each clip assemblycomprising: a capsule extending longitudinally from a proximal end to adistal end and including a channel extending therethrough; and first andsecond clip arms each extending from a proximal end to a distal end, theproximal ends being received within a channel of a capsule to be movedbetween an open tissue receiving configuration, in which distal ends ofthe clip arms are separated from one another, and a closed tissueclipping configuration, in which distal ends of the clip arms are movedtoward one another, wherein the first clip arm includes a first tissueretention feature at a distal portion thereof configured to piercethrough a target tissue when in the tissue clipping configuration andsubsequently release the target tissue when the clip arms are moved toan at least partially open configuration and the second clip armincludes a second tissue retention feature at a distal portion thereofconfigured to pierce and retain the target tissue thereon when in boththe closed tissue clipping configuration and the open tissue receivingconfiguration.
 24. The system of claim 23, wherein the first tissueretention feature includes at least one spike at a distal tip of thefirst arm and the second tissue retention feature includes two spikes ata distal tip of the second arm.
 25. The system of claim 24, wherein thespikes extend from the distal tips of the first and second arms at a 90degrees angle relative to the longitudinal axis of the clip arms. 26.The system of claim 23, wherein when the clip arms are in the closedconfiguration, spikes on opposing clip arms are configured to bestaggered.
 27. The system of claim 23, wherein the first tissueretention feature includes at least one spike at a distal tip of thefirst arm and the second retention feature includes at least one hookextending from the distal tip of the second arm.
 28. The system of claim23, wherein the second tissue retention feature includes a plurality ofbarbs extending from one of an interior surface and a side surface ofthe second clip arm.
 29. The system of claim 28, wherein at least one ofthe barbs extends at a 90 degrees angle relative to a longitudinal axisof the second clip arm.
 30. The system of claim 28, wherein an interiorsurface of the first clip arm is flat.
 31. A method of treating tissue,comprising: inserting a first clip assembly to a target site within aliving body via a working channel of an endoscope, the first clipassembly including a capsule and first and second clip arms slidablyreceive within the capsule to be movable between an open configuration,in which distal ends of the clip arms are separated from one another,and a closed configuration, in which distal ends of the clip arms aredrawn toward on another; positioning the clip arms in contact with afirst target tissue; moving the first clip assembly from the openconfiguration to the closed configuration such that a first tissueretention feature on a distal portion of the first clip arm and a secondtissue retention feature on a distal portion of the second clip armpierces through the first target tissue; moving the first clip assemblyfrom the closed configuration to the open configuration, the firsttissue retention feature releasing the first target tissue while thesecond tissue retention feature retains the first target tissue thereon;positioning the clip arms in contact with a second target tissue; andmoving the first clip assembly from the open configuration to the closedconfiguration to clip the first and second target tissues between thefirst and second clip arms.
 32. The method of claim 31, wherein thefirst tissue retention feature is a spike.
 33. The method of claim 31,wherein the second tissue retention feature is one of a plurality ofbarbs, a plurality of spikes and a hook.
 34. The method of claim 31,further comprising: loading a first clip assembly on an applicator bycoupling a control member of the applicator to the proximal ends of cliparms.
 35. The method of claim 33, further comprising: releasing the clipassembly from the applicator; and loading a second clip assembly on anapplicator by coupling a control member of the applicator to theproximal ends of clip arms.